Method of making gas



Patented May 2, 1950 METHOD OF MAKING GAS John S. Haug, Chestnut Hill, Pa., asslgnor to United Engineers & Constructors Inc., Philadelphia, Pa., a corporation of Delaware No Drawing. Application March 1, 1948,

- Serial No. 651,419

Claims.

Probably the most emcient method of gasification of solid fuel is the well known producer gas process wherein an ignited fuel bed is continuously blasted with air or preferably with a mixture of air and steam, the oxygen of the air combining with the carbon of the fuel to form CO and the steam being decomposed into hydrogen and oxygen, thereby releasin additional oxygen for immediate combination with the carbon of the fuel for forming additional carbon monoxide. The steam is thereby transformed into water gas and the endothermic heat required for the formation of the water gas serves to moderate the fire temperature and to prevent formation of hard clinkers.

Due to the presence of large proportions of nitrogen from the air blast, this gas has a calorific value of only about 120 to 160 B. t. u. per cubic feet which is considerably lower than that required for city gas consumption. It is conventional practice in gasification of coke or coal for city gas consumption to'employ the cyclic water gas process wherein the 'fuel bed is first heated by a short heavy air blast the products of which are discharged to the atmosphere, followed immediately by a steam run to make the water gas which is passed to the gas holder for storage. By thus alternately storing heat in the fire and using it to make water gas, the gas can be obtained in a relatively pure condition, that is, comparatively free from incombustible gases, termed inerts, since the nitrogen associated with the air blast and heat generation can be discharged to the atmosphere and thus its mixture with the relatively pure water gas avoided. For city gas supply, it is necessary to enrich water gas to a higher calorific power to conform to municipal and state standards, usually employing for the purpose petroleum oil, in the form of one or more of the relatively less valuable fractions produced in the refining of the crude oil, such as gas oil, residuum oil or bunker oil. To this end the heat of the blast gases, prior to their discharge to the atmosphere, is customarily stored in refractory heat storage material such as fire brick on which the oil is sprayed during the run" period and the stored heat is thus utilized to cause the gasification of the oil and the generation of oil gas which mixes with the blue gas to afford the required calorific value.

It has been proposed to generate gas, as in the producer gas process, by continuously blasting an ignited fuel bed with a gaseous mixture containing free oxygen and steam, but containng a materially higher relative proportion of free oxygen to nitrogen than that provided in the conventional producer blast of mixed atmospheric air and steam. The resulting gas. which for convenience will be termed generator gas," would have a higher calorific power than that of conventional producer gas because there would be materially less dilution of the combustible constituents of the gas by inert nitrogen. In case pure or substantially pure free oxygen were employed in admixture with steam as the gas making fluid, under pressure conditions not greatly exceeding one atmosphere absolute pressure, the generator gas then obtained would not be pure water gas, which has a theoretical content of hydrogen and 50% carbon monoxide, but would be a mixture of water gas and carbon monoxide (plus small quan' titles of CO2 and other components). The gross calorific value of the generator gas in this case, however, would be about the same as water ass. i. e. about 300 B. t. u. or more per cubic feet, since CO and H2 have about the same gross calorific value. The net calorific value would be somewhat higher than water gas due to lower hydrogen. content. The efilciency of gas generation would be considerably greater than in the case of the conventional cyclic water gas generation since the heat carried off by the nitrogen of the air blast in the cyclic process would be conserved.

In such use of a gas making fluid having a high ratio of free oxygen to nitrogen for the manufacture of city gas, it would also be necessary to consider the requirements of city gas standards as to calorific value, these being currently in the neighborhood of 520 B. t. u. per cu. ft. or higher. As noted above, an ignited fuel bed blasted with a mixture of substantially pure oxygen and steam, at ordinary pressures will produce a generator gashaving a calorifice value in the neighborhood of 300 B. t. u. per cubic foot. To enrich this gas to a calorific value meeting city gas requirements, would ordinarily require the addition thereto of oil gas resulting from the gasification of approximately 3 gallons or .more of enriching oil per 1000 cubic feet of generator gas produced.

While the generator gas leaves the fuel bed in a relatively hot condition, the above proposed gas generating procedure does not and cannot produce enough sensible heat to effect the desired gasification of so much oil, and to burn a sufficient portion of the generator gas to generate enough heat to make up the deficiency is uneconomical.

Moreover if the heat required for the above oil gasification were supplied by direct heating produced by the combustion of a sufllcient portion of the generator gas with air, the finished gas would be contaminated with nitrogen to a degree that would tend to nullify the utility of the employment in the production of the generator gas, of a gas making blast of low nitrogen content, and would tend to render necessary the gasification of additional enriching oil to compensate for the nitrogen dilution derived from the air supplied for generator gas combustion.

The mere substitution of substantially pure oxygen for air, in the combustion of a part of the generator gas to provide sufficient direct heating for the gasification of the required enriching oil, would be accompanied by the establishment of high local temperatures and generally non-uniform temperature distribution. As a, result there would be a tendency to overcrack some of the oil with unwanted production of carbon and naphthalene, while undercracking the remainder of the oil with the production of undue proportions of unsaturated gum-forming hydrocarbons, and with generally ineflicient utilization of the oil for enrichment.

The present invention contemplates an improved method for utilizing, as gas-making fluids, mixtures of free oxygen (of greater purity with respect to admixed unreactive incombustible gas than the oxygen of atmospheric air) and steam (or other fluid which reacts endothermically with hot carbon) in the production of a gas or calorific power adequate for city gas consumption, and a principal object of the invention is to provide a process of this character which will largely avoid the undesirable features and inefficiencies of the prior proposed methods as outlined above.

Other conditions being the same, the greater the freedom of the oxygen from unreactive, in combustible admixed gas, such aS nitrogen, the better. Oxygen entirely free from such diluents can be very advantageously employed if economically obtainable. Free oxygen from any suitable source may be employed. By the fractionation of liquid air, for example, oxygen of I varying degrees of purity is obtainable commercially, such as purities of from 85 or 90% to 98 or 99% or even 99.5% by volume, and possibly higher. While the use of free oxygen in any greater concentration with respect to unreactive incombustible diluents, such as nitrogen, than that provided by the use of atmospheric air tends to reduce the quantity of inert constituents going into the finished gas, it is preferred in the practice of my invention, to employ free oxygen having a purity with respect to such unreactive, incombustible diluents, of at least by volume, preferably at least and still more preferably at least or higher, such as from to 100% by volume. Preferably the generator gas is comprised at least preponderantly of combustible constituents such, for example, as carbon monoxide and hydrogen.

For convenience the term concentrated oxygen, as hereinafter employed, is intended to mean free oxygen which has a degree of purity with respect to any accompanying unreactive, uncombustible. diluent gas, such as nitrogen, within the widest percentage range indicated in the immediately preceding paragraph.

By the term um'eactive incombustible diluent gas is meant gas such s nitrogen which neither reacts to any considerable extent with the hot carbon present in the fuel bed and/or in the gas enriching zone or with the other constituents of the generator gas or finished gas, and which if present in the finished gas does not contribute to its calorific value. Steam and carbon dioxide, for example, are not included in the term, since although, if present in the generator gas or finished gas, they do not contribute to the calorific value thereof, they, however, react with the hot carbon in the fuel bed and/or in the enriching zone to produce combustible gas, and may react with other constituents of the gas. Likewise hydrocarbon gases such as methane and ethane are not included in the term since they, for example, are neither unreactive under the conditions obtaining, nor are they incombustible.

To the general end above set forth, the invention contemplates the enrichment of generator gas, of the character described, with hydrocarbon gas produced by the pyrolysis of fluid hydrocarbon material by the aid of heat generated by the reaction with said fluid hydrocarbon material of an intimate mixture of concentrated oxygen and steam. Preferably the pyrolysis of the enriching hydrocarbon fluid is effected by the aid of heat liberated by the partial combustion thereof with said concentrated oxygen in the presence of said steam and in the presence of said generator gas, the proportions of concentrated oxygen and steam employed and the intimate mixing or blending of the reactants being such, with respect to other conditions obtaining, as to effect the desired combustion and pyrolysis reactions and to impede or prevent undesired reactions such as the production of undue proportions of gum forming'unsaturates on the one hand and undue proportions of carbon and naphthalene on the other hand.

The process may be carried out by producing generator gas as previously described by passing a mixture of concentrated oxygen and steam through an ignited fuel bed, passing the generator gas so produced from the fuel bed through an oil vaporization and pyrolyzing zone, spraying enriching oil into the flow of generator gas passing through said oil vaporization and pyrolyzing zone in the presence of an intimate mixture of concentrated oxygen and steam, the sensible heat of the generator gas furnishing part of the heat necessary to gasify the oil and part of the oil gasification heat resulting from the reaction of oil and/or oil pyrolysis products with the concentrated oxygen. Simultaneously the endothermic reaction of the intimately mixed or blended steam with the vapor phase reactants and/or with carbon produced by the pyrolysis,

serves to control the temperature of the reaction and hence the temperature under which the oil pyrolysis takes place, as well as serving to utilize the carbon produced and to prevent its accumulation.

An illustrative manner of operation as carried out in the conventional carburetted water gas apparatus comprises producing generator gas by continuously passing a mixture of concentrated oxygen and steam through an ignited fuel bed in the generator, continuously passing the resulting generator gas from the generator into the carburetter, continuously admitting finely divided oil or other fluid hydrocarbon material into the carburetter and into the flow of the generator gas therethrough in the presence of an intimate mixture of concentrated oxygen and steam, so proportioned as to effect the desired degree of partial combustion and pyrolysis of the oil, continuously passing the resulting vapor phase mixture through the superheater for the further pyrolysis or fixing of the hydrocarbon constituents thereof, and continuously leading off the resulting enriched gas from the superheater through appropriate condensing and purifying apparatus to storage or other utilization.

The carburetter and/or the superheater may be provided with refractory heat storage material such as checkerbrick to provide contact surface and to act as a heat storage fly wheel, or alternatively maybe empty, the contact and heat storage effect being provided by the hot refractory lining walls assisted, if desired, by cross wall and/or pier structures.

It is to be understood that the functions of the carburetter and superheater merge one into the other, and that they may be consolidated in a single vessel or further subdivided, if desired. Alternatively either the carburetter or the carburetter and superheater may be consolidated with the generator, the necessary space being provided above the generator fuel bed for the desired enriching of the gas issuing from the fuel bed.

It has been found that if oil is burned with oxygen alone, the reactivity of the oxygen with the oil tends to make the combustion extremely intense with the production of high local temperatures which are undesirable for reasons set forth above. It is known also that the cracking of heavier hydrocarbons to make lighter ones is accompanied by the production of carbon which, if not itself gasified, will result in a considerable loss to the process. It is in these respects that the steam introduced with the oxygen and oil in the aforedes'cribed process functions. The steam is present in sufficient quantity to immediately absorb some of the excess local heat produced in the partial combustion of the oil and acts as a diluent and to distribute the heat throughout the gasification chamber. In addition carbon produced in the partial combustion and cracking of the oil will react with the steam under the temperature conditions obtaining with the formation of water gas. The liberated carbon is thus in large part or wholly reacted to produce gaseous compounds, the endothermic character of the reaction resulting in the absorption of still further excess local heat to still further temper the intensity of the reaction. The steam by reaction with hydrocarbon material further serves in the 4 formation of reaction products containing carbon, hydrogen and oxygen.

In a preferred procedure, the oxygen and steam are premixed in the proportions required to maintain the proper temperatures and temperature distribution under the other conditions obtaining and the resulting mixture is blended intimately with the enriching oil, by means, for example, of an atomizing burner. Alternatively the oil and steam may be mixed together in such a burner and concentrated oxygen supplied to the resulting mixture in such a manner as to mix said concentrated oxygen intimately therewith. It is generally inadvisable to mix highly concentrated free oxygen alone with the oil because of the danger of premature combustion or even of explosion. Therefore, in the present invention when the oxygen comes in contact with the oil, steam is present, either having been premixed with the oxygen prior to contact thereof with the oil, or having been premixed with the oil prior to contact thereof with the oxygen.

Since a large part of the heat required for the vaporization and cracking of the oil is supplied by the reaction between 011 and/ or pyrolysis products thereof and the oxygen, the intensity of the pyrolysis of the oil may be increased or decreased. other conditions being the same, by increasing or decreasing the ratio of free oxygen to oil.

The range of operations is determined by the criterion that the mixture of the generator gas produced from solid fuel with the enriching gas produced from fluid hydrocarbon material shall conform to the desired calorific value, said desired calorific value being higher than that of the generator gas and lower than that of the enriching gas. Within this range, however, there may be very considerable variation in the calorific value of the enriching gas and in the proportion of enriching gas contained in the finished gas. The finished mixedgas of a given calorific value may contain a small content of high calorific value enriching gas or a large content of lower calorific value enriching gas. By this means the process of manufacture may be adapted to the market. If solid fuel is cheap and plentiful and oil is scarce and high in cost, enriching gas of relatively high calorific value will be desirable so that less oil gas will'be required. If, on the other hand, fuel is scarce and high in cost, as, for example, in the case of a strike, and oil is more available and cheaper, the ratio of oil gas enricher may be higher and its calorific value lower.

It is to be noted also that when making a lower calorific value enriching gas of larger proportionate volume in the finished gas, the total amount of mixed gas will be increased. This method of operation may be used, therefore, even should it not be most economical in production cost, when a high rate of gas making is: the controlling consideration as in the case when a peak in gas demand occurs which may only persist for a few days and which would not justify the cost of installing additional equipment.

The foregoing description of operations in standard or modified carburetted water gas apparatus has the advantage that the presence, in the zone of oil vaporization and pyrolysis, of the generator gas made from solid fuel, reduces the partial pressure of the oil vapors and of the vapor phase products of oil pyrolysis, so that a greater proportion of the hydrocarbon material of the oil is vaporized, and more hydrocarbon material is retained in vapor phase in the mixed gas, with resulting improved efliciency of enrichment. It is probable that some gaseous partial combustion products of hydrocarbon material are produced which contain carbon, hydrogen and. oxygen, which is also advantageous to gas making economy.

In an example of operations in accordance with the present invention, an ignited fuel bed of coke in a water gas generator is blasted with a mixture of concentrated oxygen and steam, the concentrated oxygen having, for example, an oxygen content greater than by volume, and the proportion of steam to pure oxygen in said mix ture being approximately 2 parts of steam to 1 part of pure oxygen, by volume. The resulting generator gas of approximately 295 B. t. u. per cubic foot is passed into and through a checker filler carburetter and a checker filled superheater and carburetted therein.

As the generator gas passes through the carburetter and superheater, it isienrichedl with oil gas produced by introducing into the carburetter top, through an atomizing burner, gas oil together with an intimate mixture of concentrated oxygen and steam, the concentrated oxygen having, for example, an oxygen content greater than .neighborhood of 370 cubic feet of enriching gas of approximately 1130 B. t. u. per cubic foot, per 1000 cubic feet of generator gas, producing a mixed gas of approximately 520 B. t. u. per cubic foot. Those skilled in the art will readily understand how to adjust the relative proportions of oil, oxygen and steam to produce the desired oil gasification.

Increasing the proportion of oxygen with respect to the oil tends to increase the degree of combustion thereof and to decrease the calorific .gas from the liberated carbon, other conditions being the same.

Temperature conditions maintained in the carburetter and superheater will necessarily vary with the degree of oil pyrolysis to be effected therein, as well as with the enriching oil employed. Average temperatures of the order of those employed in carburetted water gas practice, such for example, as average superheater base temperatures of the order of 1400 to 1550" F. are given by way of example but not by way of limitation.

The proportion of concentrated oxygen to steam introduced into the oil vaporizing and gasiiication zone may be widely varied depending upon other conditions. Proportions of from 1 part of steam to 3 parts of concentrated oxygen by volume to 3 parts of steam to 1 part of concentrated oxygen by volume are given by way of ilustration, but greater and smaller proportions of steam may be employed.

Since the use of concentrated oxygen has a tendency to localize combustion in a small section of the fuel bed toward the base thereof, it may be desirable to interrupt'the continuity of the production of generator gas with concentrated oxygen and steam occasionally to make a blow with air for the purpose of conditioning the fire by improving the uniformity of temperature distribution therein, and the use of terms such as continuous" or continuously or the like in the claims is not intended to preclude such occasional interruptions. The resulting blast gas, which will contain a relatively large proportion of nitrogen will usually be passed through the stack to the'atmosphere after its combustion with secondary air in the carburetting vessel or vessels.

On the other hand, if the blow" is short and the blast gas is relatively high in CO, it maybe passed without combustion through the carburetting vessel or vessels to storage, in the manner of the well known blow-run" and may be carburetted in the passage through the set in the same manner as previously described in connection with the carburetting of the generator gas. Whether or not this blast gas may be passed to storage will depend .upon the quantity of diluent nitrogen, which may betolerated in the stored gas.

Whenever it is desirable to produce a carburetted combustible gasof higher caloriflc value than ordinary producer gas, inv which carburetted gas a relatively high specific gravity due to a relatively high nitrogen content is not objectionable,

instead of employing concentrated oxygen in my above described gas making procedure, I may employ oxygen enriched air of lower oxygen content, or even air, either in the generation of the producer gas in the fuel bed, for example, by the use of a blast of air and steam, or in the carburetting of-' the fuel gas produced from solid fuel, by the partial combustion of fluid-hydrocarbon material, for example, by reaction of a mixture of air and steam therewith in a hydrocarbon pyrolyzing zone through which the fuel gas is passed, or in both the generation of the fuel gas and its carburetting.

It will be understood by those skilled in the art that because of the high proportion of nitrogen present, the finished gas will be of relatively high specific gravity as compared'to usual carburetted water gas, particularly in case air isemployed instead of concentrated oxygen in both the fuel gasgeneration and its enriching. Also because of the nitrogen present, a considerably larger quantity of a given hydrocarbon enriching material must be employed to provide a given calorific value in the finished gas.

While the process as more particularly described above proposes to utilize steam, it is apparent that the process may be conducted by use of some other fluid which reacts endothermically with hot carbon of the fuel bed or from the oil with the production of combustible gas, such, for example, as CO: which reacts with hot carbon to form CO. In theclaims, the term an endothermic gas-making fluid is intended to mean a vapor phase fluid capable of reacting endothermically with the ignited carbon of the fuel bed or the ignited carbon liberated from the hydrocarbon enriching material to produce combustible gas.

In the specification and claims the term gasification" as applied to the pyrolysis of petroleum oil does not imply that all of the oil is converted into material which is gaseous under standard conditions of temperature and pressure, since in the preferred pyrolysis very considerable proportions of the products of pyrolysis may be liquid under standard conditions of temperature and pressure, and condense out of the gas as tar, light oil, drip oil etc. upon subjecting the gas to cooling and/or compression prior to utilization.

I claim:

1. In the manufacture of carburetted combustible gas, the process which comprises continuously passing a gaseous mixture of oxygencontaining combustion-supporting gas and an endothermic gas-making fluid into an ignited bed of solid fuel to produce a fuel gas having an autogenous elevated temperature and containing insufficient sensible heat to effect thereby the gasification of suflicient oil for its carburetting, continuously passing said hot fuelgas through a hydrocarbon pyrolizing zone, and therein continuously enriching said fuel gas with hydrocarbon gas produced therein by the pyrolysis therein of fluid hydrocarbon material in the presence of said hot fuel gas passing therethrough by the aid of the autogenous sensible heat of said fuel gas and by the aid of additional heat continuously produced by the reaction in said pyrolizing zone of fluid hydrocarbon material with an intimate mixture of additional oxygen-contain ng combustionsupporting gas and additional endothermic gasmaking fluid, the proportion of combustion-supporting gas in the gas-making fluid introduced into the fuel bed and into said hydrocarbon pyrolizing zone being sufficient to maintain the continuity of the gas-making reactions therein.

2. In the manufacture of carburetted combustible gas, the process which comprises continuously passing a gaseous mixture of concentrated oxygen and an endothermic gas-making fluid into an ignited bed of solid fuel to produce a fuel gas having an elevated temperature resulting from the endothermicity of its generation, continuously passing said hot fuel gas from said fuel bed through a hydrocarbon pyrolizing zone, and therein continuously enriching said fuel gas with hydrocarbon gas produced by the pyrolysis of fluid hydrocarbon material in said pyrolizing zone in the presence of said hot fuel gas by the aid of sensible heat contained in said fuel gas and evolved in the continuous gas-making reaction between said solid fuel and said concentrated oxygen and by the aid of additional heat continuously produced by the reaction in said pyrolizing zone of fluid hydrocarbon material with an intimate gaseous mixture of additional concentrated oxygen and additional endothermic gas-making fluid, contact between said fluid hydrocarbon material and said additional concentrated oxygen being substantially avoided in the absence of said additional endothermic gas-making fluid.

3. In the manufacture of carburetted combustible gas, the process which comprises continuously passing a gaseous mixture of concentrated oxy en and steam into an ignited bed of solid fuel to produce a fuel gas comprised preponderantly of carbon monoxide and hydro en and having a higher ratio of carbon monoxide to hydrogen than that of blue water gas, continuously leading off said fuel gas from said fuel bed at elevated temperature due to autogenous sensible heat continuously evolved in the gasmaking combustion of said fuel with said concentrated oxygen, continuou ly passing said hot fuel gas through a heated hydrocarbon pyrolizing zone, and therein continuously carburetting said fuel as with an enriching gas of higher calorific value than that of said fuel gas and continuously produced bv the pyrolvsis of petroleum oil in said pvrolizing zone in the presence of said hot fuel gas bv the aid of said auto enous sensible heat and hv t e aid of additional heat continuouslv roduced bv the reaction in said pyrolizing zone of said petroleum oil with an intimate gaseous mixture of additional concentrated oxygen and additional steam, while substantially avoiding contact between said oil and said additional concentrated oxygen in the absence of said additional steam.

4. In the manufacture of carburetted combustible gas, the process which comprises continuously passing a gaseous mixture of concentrated oxygen and steam into an ignited bed of solid fuel to produce a fuel gas comprised preponderantly of carbon monoxide and hydrogen and. having a higher ratio of carbon monoxide to hydrogen than that of blue water gas, continuously leading off said fuel gas from said fuel bed at elevated temperature due to autogenous sensible heat continuously evolved in the generation of said fuel 10 gas by the combustion of said fuel with said concentrated oxygen, continuously passing said hot fuel gas through a heated hydrocarbon pyrolizing zone, and therein continuously carburetting said fuel gas with an enriching gas of higher caladditional heat continuously produced by the reaction in said pyrolizing zone of said petroleum oil with an intimate gaseous mixture of additional concentrated oxygen and additional steam, while substantially avoiding contact between said oil and said additional concentrated oxygen in the absence of said additional steam.

5. In the manufacture of carburetted combustible gas, the process which comprises continuously passing a mixture of concentrated oxygen and steam into an ignited bed of solid fuel to produce a fuel gas comprised preponderantly of carbon monoxide and hydrogen and having a higher ratio of carbon monoxide to hydrogen than that of blue water gas, continuously leading ofl said fuel gas from said fuel bed atelevated temperature directly imparted thereto by, the fuel gasgenerating combustion of said fuel with said concentrated oxygen, continuously passing said hot fuel gas containing said sensible heat thus produced through a heated hydrocarbon pyrolizing zone, and separately, simultaneously and continuously introducing into said hydrocarbon pyrolizing zone during the passage of said hot fuel gas therethrough finely divided petroleum oil and a preformed intimate mixture of additional concentrated oxygen and additional steam to generate an enriching fuel gas of higher caloriflc value than that of said fuel gas by the aid of the autogenous sensible heat in said fuel gas and by the aid of additional heat continuously evolved in the reaction of said last-mentioned mixture and said oil, thereby continuously carburetting said fuel gas with said enriching gas to produce carburetted combustible gas of higher calorific value than said fuel gas.

6. In the manufacture of carburetted combustible gas, the process which comprises continuously passing a gaseous mixture of concentrated oxygen and steam into an ignited bed of solid fuel to produce a fuel gas comprised preponderantly of carbon monoxide and hydrogen. and having a considerably higher ratio'of carbon monoxide to hydrogen than that of blue water gas, continuously leading said fuel gas from said fuel bed at elevated temperature resulting directly from the sensible heat contained therein as a result of the continuous gas-making combustion of said fuel with said concentrated oxygen, con tinuously passing said hot fuel gas through a heated hydrocarbon pyrolizing zone and continuously carburetting said fuel gas therein with an enriching gas of higher calorific value than that of said fuel gas; said enriching gases being pro: duced in said pyrolizing zone in the presence of said fuel gas passing therethrough by contacting with additional concentrated oxygen an intimate mixture of finely divided petroleum oil and steam formed in the substantial absence of concentrated oxygen to vaporize and gasify said petroleum oil by the aid of said autogenous sensible heat in said fuel gas and by the aid of additional heat continuously produced by the partial combustion in said pyrolizing zone with said additional concentrated oxygen of hydrocarbon ma- 11 terial derived from said oil, said additional steam by continuous reaction with carbon produced by the pyrolysis of said oil gasifying said carbon and moderating the intensity of said partial combustion.

7. In the manufacture of carburetted combustible gas, the process which comprises continuously passing a gaseous mixture of concentrated oxygen and steam into an ignited bed of solid fuel to produce a fuel gas comprised preponderantly of carbon monoxide and hydrogen and containing a considerably higher ratio of carbon monoxide to hydrogen than that of blue water gas, continuously leading off said fuel gas from said fuel bed at an elevated temperature resulting directly from the sensible heat contained therein as a result of the continuous evolution of carbon monoxide in said fuel gas by the combustion of said fuel with said concentrated oxygen, continuously passing said hot fuel gas through a heated hydrocarbon pyrolizing zone and continuously carburetting said fuel gas therein with an enriching gas of higher calorific value than that of said fuel gas; said enriching gas being continuously produced in said pyrolizing zone in the presence of said fuel gas passing therethrough by contacting finely divided petroleum oil with an intimate preformed mixture of additional concentrated oxygen and additional steam to vaporize and gasify said oil by the aid of said sensible heat imparted to said fuel gas in the combustion reaction of its generation and by the aid of additional heat continuously generated by the partial combustion with said additional concentrated oxygen in said 'pyrolizing zone of hydrocarbon material derived from said oil. said additional steam by continuous reaction with carbon produced in the pyrolysis of said oil gasify- I ing said carbon and modifying the intensity of said partial combustion.

8. In the manufacture of carburetted combustible gas, the process which comprises of continuously blasting an ignited bed of solid fuel with a gaseous mixture of concentrated oxygen and steam to produce a fuel gas comprised preponderantly of carbon monoxide and hydrogen and con taining a considerably higher ratio of carbon monox de to hydrogen than that of blue water gas, leading ofi said fuel gas in a heated condition due to sensible heat directly imparted thereto by the combustion reactions of said concentrated oxvgen with said fuel resulting in the generat on of a portion of the carbon monoxide content of said fuel gas, cont nuously passing said hot fuel gas through a heated hydrocarbon pyrolizing zone, and simultaneously continuously carburetting said fuel gas in passage therethrough with an enriching gas of higher calorific value than said fuel gas, said enriching gas being produced by the continuous pyrolysis of fluid hydrocarbon material in said Dyrolizing zone during the passage of said fuel gas therethrough by the aid of said sensible heat in said fuel gas which was directly evolved therein in its generation by the combustion reaction of said concentrated oxygen with said fuel and by the aid of heat produced by the continuous reaction in said pyrolizing zone of fluid hydrocarbon material with a preformed intimate mixture of additional concentrated oxygen and additional steam, said concentrated oxygen employed in generating said fuel gas from solid fuel and in generating said enriching gas from hydrocarbon material having a purity with respect to unreactive lncombustible dilution of at least 85% by volume.

9. The process for producing carburetted combustible as suitable for distribution as city gas by generating and carburetting a carbon monoxide-hydrogen gas having a considerably higher ratio of carbon monoxide to hydrogen than that of blue water gas which comprises, continuously and simultaneously introducing concentrated oxygen and steam into upstream and downstream portions respectively of a gas-making path, continuously passing said concentrated oxygen and steam introduced into said upstream portion of.

troleum oil required to carburet said resulting gas, continuously passing said hot carbon monox de-hydrogen gas into'said downstream portion of said gas-making path, simultaneously in troducing petroleum oil into said downstream portion of said path, and reacting said oil therein in the presence of said hot gas with said concentrated oxygen and steam introduced to said downstream portion of said path to effect the gasification of said oil in part by the aid of said sensible heat imparted to said hot 'gas in the combustion reaction of its generation and in part by the partial combustion of said oil with said last-mentioned concentrated oxygen, the proportion of the concentrated oxygen in the gas-making fluids continuously introduced into said upstream and downstream portions respectively of said path being sufficiently high to maintain by continuous combustion therein the continuity of the gasmaking reactions therein.

10. The process for producing a carburetted combustible gas suitable for distribution as city gas by generating and carburetting a carbon monoxide-containing gas which comprises, continuously and simultaneously introducing into upstream and downstream portions respectively of a gas-making path concentrated oxygen and an endothermic gas-making fluid capable of reacting with hot carbon to produce carbon monoxide, continuously passing said concentrated oxygen and said endothermic gas-making fluid introduced into said upstream portion of said path in admixture through an ignited fuel bed disposed therein to generate continuously said carbon monoxide-containing gas by the preponderatingly exothermic reaction of said mixed concentrated oxygen and said endothermic gas-making fluid with said fuel, continuously leading off from said fuel bed the resulting gas at elevated temperature due to sensible heat directly imparted thereto by the gas-making combustion reaction of its generation, said sensible heat being insufficient to effect the vaporization and gasification of the 011 required for the carburetion of said resulting gas, continuously passing said hot gas into said downstream port on of said path, simultaneously introducing finely divided petroleum oil into said downstream portion of said path and reacting said oil therein in the presence of said hot gas with said concentrated o ygen and steam introduced to saiddownstream portion of said path to effect the gasification of said oil in part 13 by said autogenous sensible heat in said gas and in part by the partial combustion of said oil with said last-mentioned concentrated oxygen, contact between said oil and said concentrated ox en in the absence of said last-mentioned endothermic gas-making fluid being minimized and the proportion of concentrated oxygen in the gasmaking fluids continuously introduced into said upstream and downstream portions respectively of said path being sufficiently high to maintain by continuous combustion therein the continuity of the gas-making reactions therein.

11. In the generation of combustible gas by the simultaneous continuous blasting of an ignited fuel bed with concentrated oxygen and an endothermic gas-making fluid capable of reacting with hot carbon to form carbon monoxide, the step which comprises occasionally interrupting the continuity of the passage of concentrated oxygen and said endothermic gas-making fluid into said fuel bed by blasting said fuel bed with air.

12. A continuous process for the manufacture of carburetted fuel gas suitable for distribution as city gas, which comprises continuously generating a fuel gas composed preponderantly of carbon monoxide and hydrogen and having a higher ratio of carbon monoxide to hydrogen than that of blue water gas by continuously blasting an ignited bed of solid fuel with a gaseous mixture of concentrated oxygen and steam, leading off the resulting fuel gas from the fuel bed at an elevated temperature due to sensible heat directly imparted to said fuel gas by the gas-making combustion reaction of said concentrated oxygen with said fuel, and continuously passing said hot fuel gas through a heated oil pyrolyzing zone, and continuously carburetting said fuel gas therein with enriching gas of calorific value sufficiently high to enrich said fuel gas sufllciently for distribution as city gas by gasifying finely divided petroleum oil in said heated oil pyrolyzing zone during the passage of said fuel gas therethrough by thermal decomposition and by partial combustion with additional concentrated oxygen in the presence of intimately mixed additional steam while substantially avoiding contact between said oil and said additional concentrated oxygen in the absence of said additional steam, the heat required for said oil gasiflcation being in part supplied by said sensible heat in said fuel gas and in part by the partial combustion of said oil with said additional concentrated oxygen.

13. A process according to claim 12, in which the finely divided petroleum oil is intimately mixed with said additional steam prior to contact between said oil and said additional concentrated oxygen.

14. A process according to claim 12, in which the additional concentrated oxygen is intimately mixed with said additional steam prior to contact between said oil and said additional concentrated oxygen.

15. In the manufacture of carburetted combustible gas, the process which comprises generating fuel gas by blasting an ignited bed of solid fuel with a gaseous mixture of concentrated oxygen and an endothermic gas-making fluid, passing said fuel gas through a heated hydrocarbon pyro-, lyzing zone and carburetting said fuel gas during passage therethrough with enriching gas of higher calorific value than that of said fuel gas, said enriching gas being produced by reacting fluid hydrocarbon material in said pyrolyzing zone during the passage of'said fuel gas therethrough with a gaseous mixture of additional concentrated oxygen and additional endothermic gas-making fluid, occasionally interrupting the continuity of the blasting of said fuel bed with concentrated oxygen, and steam by blasting said fuel bed with air to establish more uniform distribution of temperatures vertically through said fuel bed.

JOHN S. HAUG.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 625,588 Moynihan May 23, 1899 1,547,191 Abbott July 28, 1925 1,689,940 White Oct. 330, 1928 2,166,094 Johnson et a1. July 11, 1939 

1. IN THE MANUFACTURE OF CARBURETTED COMBUSTIBLE GAS, THE PROCESS WHICH COMPRISES CONTINUOUSLY PASSING A GASEOUS MIXTURE OF OXYGENCONTAINING COMBUSTION-SUPPORTING GAS AND AN ENDOTHERMIC GAS-MAKING FLUID INTO AN IGNITED BED OF SOLID FUEL TO PRODUCE A FUEL GAS HAVING AN AUTOGENOUS ELEVATED TEMPERATURE AND CONTAINING INSUFFICIENT SENSIBLE HEAT TO EFFECT THEREBY THE GASIFICATION OF SUFFICIENT OIL FOR ITS CARBURETTING, CONTINOUSLY PASSING SAID HOT FUEL GAS THROUGH A HYDROCARBON PYROLIZING ZONE, AND THEREIN CONTINUOUSLY ENRICHING SAID FUEL GAS WITH HYDROCARBON GAS PRODUCED THEREIN BY THE PYROLYSIS THEREIN OF FLUID HYDROCARBON MATERIAL IN THE PRESENCE OF SAID HOT FUEL GAS PASSING THERETHROUGH BY THE AID OF THE AUTOGENOUS SENSIBLE HEAT OF SAID FUEL GAS AND BY THE AID OF ADDITIONAL HEAT CONTINOUSLY PRODUCED BY THE REACTION IN SAID PYROLIZING ZONE OF FLUID HYDROCARBON MATERIAL WITH AN INTIMATE MIXTURE OF ADDITIONAL OXYGEN-CONTAINING COMBUSTIONSUPPORTING GAS AND ADDITIONAL ENDOTHERMIC GASMAKING FLUID, THE PROPORTION OF COMBUSTION-SUPPORTING GAS IN THE GAS-MAKING FLUID INTRODUCED INTO THE FUEL BED AND INTO SAID HYDROCARBON PYROLIZING ZONE BEING SUFFICIENT TO MAINTAIN THE CONTINUITY OF THE GAS-MAKING REACTIONS THEREIN. 